This online combinations calculator allows users to find the number of ways of choosing r unordered outcomes from n possibilities - nCr or C(n,r).
Type of Material:
Simulation
Recommended Uses:
This resource can be used for individual study and in-class demonstration, and practice and review.
Technical Requirements:
Any browser.
Identify Major Learning Goals:
The purpose of this site is to allow users to calculate the number of combinations of n objects taken r at a time, using the standard combinations formula.
Target Student Population:
High School, College General Ed, College Lower Division
Prerequisite Knowledge or Skills:
College Algebra
Content Quality
Rating:
Strengths:
This combinations calculator allows users to quickly calculate the number of combinations of n objects taken r at a time. It allows the user to select n and r and then applies the standard C(n,r) formula to calculate the answer. A step-by-step solution is provided. The side also includes a brief explanation of what the calculator is calculating as well as several examples. Users can click the “Get a Widget for this Calculator” button to obtain the code for inserting this calculator in a website.
Concerns:
Although the title includes the notation nCr, the text uses C(n,r).
The review material could be improved by including a quick explanation of the combinations formula.
Potential Effectiveness as a Teaching Tool
Rating:
Strengths:
In addition to step by step explanations in the calcultaor itself, the website inludes a selection of applications with alternate solutions and explanations.
This would be a great resource for students wanting to review or verify homework solutions. It could also be used for in-class demonstrations.
Concerns:
None
Ease of Use for Both Students and Faculty
Rating:
Strengths:
Simple and effective.
The calculator layout is simple and easy to use.
Concerns:
There is an advertisement displayed next to the calculator, but it is not distracting.
Creative Commons:
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